<!DOCTYPE html>
<meta charset="utf-8">
<link rel="author" title="David Shin" href="mailto:dshin@mozilla.com">
<link rel="author" href="https://mozilla.org" title="Mozilla">
<style>
  body { margin: 0; }
  .cb {
    position: relative;
    inline-size: 45px;
    block-size: 40px;
    background: lightblue;
    border: solid gray;
    border-width: 1px 2px 3px 4px;
    float: left;
    margin-right: 5px;
  }
  .parent {
    inline-size: 35px;
    block-size: 30px;
    background: orange;
  }
  .abspos {
    inline-size: 20px;
    block-size: 15px;
    background: pink;
  }

  .vrl {
    writing-mode: vertical-rl;
  }
  .vlr {
    writing-mode: vertical-lr;
  }
  .htb {
    writing-mode: horizontal-tb;
  }

  .ltr {
    direction: ltr;
  }
  .rtl {
    direction: rtl;
  }

  .sep {
    clear: both;
    display: block;
    height: 5px;
  }
</style>
<body>
  <div class="cb htb ltr">
    <div class="parent htb ltr">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb htb ltr">
    <div class="parent htb rtl">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb htb ltr">
    <div class="parent vlr ltr">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb htb ltr">
    <div class="parent vlr rtl">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb htb ltr">
    <div class="parent vrl ltr">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb htb ltr">
    <div class="parent vrl rtl">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="sep"></div>

  <div class="cb htb rtl">
    <div class="parent htb ltr">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb htb rtl">
    <div class="parent htb rtl">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb htb rtl">
    <div class="parent vlr ltr">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb htb rtl">
    <div class="parent vlr rtl">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb htb rtl">
    <div class="parent vrl ltr">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb htb rtl">
    <div class="parent vrl rtl">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="sep"></div>

  <div class="cb vlr ltr">
    <div class="parent htb ltr">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb vlr ltr">
    <div class="parent htb rtl">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb vlr ltr">
    <div class="parent vlr ltr">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb vlr ltr">
    <div class="parent vlr rtl">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb vlr ltr">
    <div class="parent vrl ltr">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb vlr ltr">
    <div class="parent vrl rtl">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="sep"></div>

  <div class="cb vlr rtl">
    <div class="parent htb ltr">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb vlr rtl">
    <div class="parent htb rtl">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb vlr rtl">
    <div class="parent vlr ltr">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb vlr rtl">
    <div class="parent vlr rtl">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb vlr rtl">
    <div class="parent vrl ltr">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb vlr rtl">
    <div class="parent vrl rtl">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="sep"></div>

  <div class="cb vrl ltr">
    <div class="parent htb ltr">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb vrl ltr">
    <div class="parent htb rtl">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb vrl ltr">
    <div class="parent vlr ltr">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb vrl ltr">
    <div class="parent vlr rtl">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb vrl ltr">
    <div class="parent vrl ltr">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb vrl ltr">
    <div class="parent vrl rtl">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="sep"></div>

  <div class="cb vrl rtl">
    <div class="parent htb ltr">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb vrl rtl">
    <div class="parent htb rtl">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb vrl rtl">
    <div class="parent vlr ltr">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb vrl rtl">
    <div class="parent vlr rtl">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb vrl rtl">
    <div class="parent vrl ltr">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="cb vrl rtl">
    <div class="parent vrl rtl">
      <div class="abspos"></div>
    </div>
  </div>
  <div class="sep"></div>
</body>
